Air-brake.



n Nq. 761,651.

J. w. BINGLEY.

AIR BRAKE.

PATBNTBD JUNE 7, 17904.

APPLIUATION FILED 00T.1B, 1903.

No ',lonym.

` ze 15 L9 iNo. 761,651.

Patented .rune 7,1904; i

UNITED STATES vPATENT OFFICE.

JOHN W. BINGLEY, or WATERTOWN, NEW YORK, AssieNoE To NEW YORK AIR BRAKE COMPANY, A CORPORATION OF NEW JERSEY.

:A1B-BRAKE.

SPECIFICATION forming part of Letters Patent No. 761,651, dated June '7, 1904.

Application filed OCl'JObBI 16, 1903.

T all whmn it may concern:

" Watertown, county of Jefferson, and State of New York, have invented an Improvement' in Air-Brakes, ot' which the following description,Y in connection with the accompanying drawings, is a specification, like numerals on the drawings representing like parts. E,

This invention relates to an air-brake apparatus,` and is shown as employed in an apparatus of the kind commonly known as the automatic air-brake in which the brakecylinder is charged with air from an auxiliary reservoir .on theA car under control of a triple valve coperating withl the train-pipe, auxiliary reservoir, and brake-cylinder to cause the brakes to. vbe applied and released in response to changes in pressure of air in the train-pipe,

which may-.be controlled by the engineer. The present invention relates, mainly, to an appliance tol be used in connection withvthe brake-cylinder or with the passage through which air is' admitted to and exhausted from thebrake-cylinder in the operation of applying and releasing the brakes, and is especiallyv applicable to brakes designed fornuse on trains running at high speed. e. For very fast running trains .it` has been found desirable to provide greater power for the brakes than is employed in connection with rolling-stock of the same character which is regularly runat a considerably lower speed, and one way oi' providing for increased power hof the brakes is to increase the air-pressure i employed in the system beyond that commonly used on trains regularly running at a lower speed. For example, an equipment designed for use on trains regularly running at about forty miles an hour as a maximum and having the standard or normal air-pressure in the l train-pipe and auxiliary reservoirs seventy Vpounds might be used, with an air-pressureoi' one hundred and ten pounds for trains regularly running at a maximum speedy of sixt miles or more. In emergency applications of the brakes the maximum pressure should be obtained in the brake-cylinders as promptly as possible, and

with a high-speed equipment the pressure in Serial No. 177,317. (No model.)

the brake-cylinders produced in emergency applications of the brakes may be sixty per cent. ormore greater than that commonly employed in a similar equipment as used on trains `normally running at a considerably lower f speed.

While the increased brake-cylind er pressure is effective and desirable to reduce the speed v of a rapidly-running train as soon as possible,

it is likely to give too great braking force after the speed of the train has been materially reduced and might then cause the locking of the "wheels, so that they 4would slide on the rails,

thus damaging the wheels and acting less effectively to bring the train to al standstill than it' the braking force were just less than that ywhich is sufficient to lock the wheels against rotation.

The present invention 1s embodied 1n an apparatus which operates automatically to re- :duce the pressure in the brake-cylinder to a predetermined and regulable amount at the end oi' a predetermined and regulable period of time after the brakes have been applied with,

maximum force. Thus the brakes may be applied with adequate force to be very eiective in checking the speed of the train when running at a high rate oi' speed-f0r example, sixty Imiles an hour or more-and after the brakes have remained applied with a maximum force a sufiicient lengthof time materially to reduce the speed of the traine-for example, to a speed of from thirty to forty miles an h0ur-the braking pressure is promptly reduced to an amount which will be more effective and reliable fo n bringing the train to a standstill from .the lower speed than. themaximum braking force originally applied. l

Theapparatus forming the subject of this inventionimay also serve automatically to relieve Lthe pressure in the` -brake cylinder. in

, ,making service applications oi' the brakes,`so

tliatthe excessive or maximum pressure carriedan the system for use 1n emergency on the rapidly-running train is not effective in the brake-cylinders in making ordinary service applications of the brakes.

The apparatus'forming the subject of this invention comprises a relief-valve controllmg an exhaust or air-escape passage from the brake-cylinder and operating like an ordinary safety-valve to open when subjected to pressure above a predetermined amount and to close when the pressure falls by reason of the escape through the open relief-valve to a predetermined amount, said relief-valve being combined. with appliances which render the brake-cylinder pressure ineffective to open th e relief-valve until after a deiinite period of time has elapsed with the brake-cylinder containing a pressure greater than that required to open the relief-valve.

Figure 1 is a longitudinal section of an airbrake appliance forming the subjectof this invention, the parts being shown in the normal position occupied when the brakes are released, which is also the position occupied in service applications of the brakes, and for a definite time interval after an emergency applieation of the brakes has been made and again after the brake-cylinder pressure has been relieved. Fig. 2 is a similar section of the main operative parts of the device in the position occu pied when the relief-valve is opened to relieve the pressure in the brakecylinder and 4cause it to be diminished from the unusual lor excessive amount employed in making an emergency application of the brakes to a predetermined lower pressure which may be regarded as the maximum pressure in the normal working of the apparatus, being the maximum pressure employed in making the regular service stops of the trains. Fig. 3 is a representation, on a small scale, vof the main components of a car equipment of the automatic air-brake system in connection with which the device forming the subject of this invention is shown as used; and Figs. 4 and 5 are sectional views showing modiiied constructions of the apparatus forming the subject lof this invention.

The working parts of the brake-cylinder relief-valve forming the subject of this invention are contained in a valve-body composed of a mai-n or base section 1 and a section 2, connected therewith and constituting the spring-chamber for the spring which determines the pressure to which the pressure in the brake-cylinder is lowered by the/operation of the relief-valve. The main -or base section 1 of the relief-valve is adapted to vbe-connected with the brake-cylinder 3 (see Fig. 3) of l"the automatic air-brake apparatus, said section 1 being shown as provided with a screw-th readed neck 4s, constituting the inlet 'duct -or tube and adapted to be connected with the head "of lthe brake-cylinder or with a passage in constant communication therewith*as, for example, the passage yfrom the ltriple valve 5 to the brake-cylinder in the usual automatic airbra-ke apparatus comprising the brake-cylinder 3, triple valve 5, train-pipe 6, and .auxiliary reservoir 7, which, in connection with the brake-rigging, constitute the equipmentI for each car.

The details of the car equipment are not shown, as they are well understood, and the relief-valve forming the subject oi the present invention may be employed in conjunction with any air-brake apparatus containing a brake-cylinder or equivalent the Huid-pressure in which causes the brakes to be applied with a braking force dependent upon the iiuidpressure exerted in the brake-cylinder.

rlhe relief-valve comprises a diaphragm 3, forming a part of a movable abutment, which is subjected at its upper side to the pressure of the fluid contained in the chamber formed in the base portion 1 of thc relief-valve and acted upon by a determinate force in opposition to said pressure, which in the construction shown is derived from the spring` E), contained in thc spring-chamber, said spring being supported to exert its pressure against the movable abutment by the spriiig-abutment 10, shown as screw-threaded and adjustable in the spring-chamber 2, for the purpose oi regulating the effective force of the spring against the movable abutment. The diaphragm proper or flexible portion 8 of the movable abutment is shown as having its outer periphery secured between the portions 1 2 of the easing, which, as shown in this instance, are screwed together, with the outer periphery oiE the diaphragm 8 lying between a shoulder formed in the base portion 1 and the end of the screwthreaded portion of the part 2 oi the easin g.

The diaphragm proper of the movable abutment has a central opening through it, the said diaphragm 8 being shown in this instance as of annular form and having its inner periphery secured between two rigid portions 11 12, the lower portion, 11, of which is provided with a seat or bearing for the spring S) `and with a tubular neck working loosely in an opening in the upper end of the springchamber and serving to `contribute to the guidance of the movable abutment when moved in response to the preponderance of pressure upon its Lipper or lower side. The portion 11 of the movable abutment is provided with a lcentral opening or passage through it IOO terminating at its upper end in a seat lor a valve 13, shown `as of the puppet-valve type, which is lightly pressed against its seat by a spring 14, contained between the valve 13 and the portion 12 of the movable abutment. Said portion 12 of the movable abutment is provided lat its upper end with an annular valve 15, which seats tightly upon a scat 16, surrounding the inlet 17 through the neck 4 to thechamber in the base portion 1 of the valve. The stem of the valve 13 works through the central opening of the annular valve 15 and in the inlet-passage 17, the said valve-stem being star-shaped or longitudinally groovcd, so as to permit the free iiow oi Huid along it.

valve-controlled partition is thus afforded bebase. portion 1 of the casing, so that with the parts in the normal position shown in Fig. 1) the fluid-pressure in the brake-cylinder, whatever it may be, is admitted through the inlet 17 andopening in the annularvalve 15 into the chamber of the valve 13, but said pressure is excluded from the main diapliragm-cliamber iii the base portion 1 of the apparatus su rrounding the upper portion 12 of the movable abutment. Thus with the parts in the normal position the movable' abutment is subjected to a fluid-pressure derived from and equal to that in the brake-cylinder over only an area equal to the area of the opening through the annular valve 15 and the'movable abutment is subjected to a further pressure in the same direction derived from .the

Huid-pressure, whatever it may be, in the diaover an area equal to the full area of the movable abutment less tlie area inclosed in the outer periphery of the annular valve 15. A

tween the portion of the apparatus that is constantly or' normally subjected to brakecylinder pressure and the Huid-pressure chamber, which has been calledthe diaphragmchamber and which contains the fluid which is the main agent in actuating the movable abutment, which itself constitutes the actuator for the two valves thus far described-namely, the pressure-excluding valve 15 and the reliefvalve proper, 13, the former of which acts, as has been already explained, to exclude the brake-'cylinder pressure from the diaphragmvchamber when said pressure-excluding valve is seated and when unseated admits the brakecylinder pressure freely into the said diapliragm-chamber, while the latter valve, 13, is the one through which the brake-cylinder pressure is relieved by exhaust or escape of air to the atmosphere, as will be hereinafter explained. A small passage or'by-pass 18 is provided to afford restricted communication between the spaces at the two sides of the partition-tliat is, from the brake-cylinder side to the diaphragm-chamber-said passage being shown in Figs.-v 1 and 2 as formedthrough the portion12 of the movable abutment. This bypass or connecting-passage 18 remains constantly open and permits the fiuid to flowfrom the brake-cylinder side of the partition into the diaphragni-chamber, in which it acts upon l the upper surface of the movable abutment in opposition to the spring 9. The passage 18 is made small, so that an appreciable determinable time will be required for the fluid entering the diaphragm-'chamber from the brakecylinder to acquire the pressure that is exerted at the brake-cylinder side of thepartition, and as itis impracticable to reduce the size 'of a fluid-passage such as 18 beyond a certain limit the time required to charge the diaphragm-chamber outside of oi' beyond the partition is increased by placing a small chamber or reservo1r 19 in communication with the diaphragm-cliainber formed in the base portion 1 of the apparatus around the partition formed by the upper portion 12 of the movable abutment. Thus when iiuid is admitted under pressure into the brake-cylinder it passes at once into the interior of the portion 12'of the movable abutment, in which the pressure is atall times substantially the same as that in the brake-cylinder and from which the iiuid under pressure passes through the passage 18 into the diaphragm-chamber and into the small reservoir 19, the aggregate capacity of which is ysuch with reference to the capacity of the passage 18 as to require a certain period of time for the-pressuretherein to equalize approximately withthe brake-cylinder pressure at the other side of the partition. phragm-chamber surrounding the portion 12 The valve13 is provided with a stop or unseating device, shown as a rod 20, the lower end of which is normally slightly above the inner surface of a cap 21, surmounting the spring-chamber 2, said cap being shown as lscrewed upon the adjusting-screw 10 for the portion 11 of the movable abutment until Y cap 21, so that in the further travel of the movable abutment the seat moves away from the valve 13, which thus becomes unseated or is opened and permits the fluid to flow pastit ITO through the opening in the portion 11 of the movable abutment and thence into the sprin'gchamber, which is provided with one or more vent-passages 22 to the external atmosphere.

The operation of the apparatus is'as follows: The spring 9 is adjusted to connterbal- .ance a pressure on substantially the full area of the movable abutment 8 which is the maximum pressure which it is desired should be produced in the brake-cylinder in service applications of the brakes and is the pressure to which the iuid in the brake-cylinder should be lowered after it has been applied for a predetermined time at a greater pressure for the eighty-live'pounds to the square inch, this being the pressure of equalizationof the fluid normally carried. in: the-auxiliary reservoir when expanded into the brake-cylinder-when placed: and maintained fin: communication'` therewith, as in making an emergency appli cation off thebrake. The springf91will: then. be adjusted to just counterbalancewhen in normal position, as shown in Fig'. 1, apressureof sixty pounds to the square-inch on=themov able abutment.. The-volume or capacity of the space beyondthepartition from the brake-cyl?- inder, including the-space in the baseportion 1 of the valve-casing andin the supplemental: reservoir or chamber 19, freely communicating therewith,I is so proportioied with. reference tothe-size of the passage 18 that it will' require the desired, lengtlr of time`say, for

example, ten` seconds-that the-brakes shouldf remain` appliediwith the-additional:v force used incase ofv emergency before the said. space` will be charged by flow of air from the brakecylinderA through the passage 18 up to: the pressure, assumed tobe sixty. pounds, to which the fluid in the brake-cylinder is` to. be lowered after the. brakes have-remained? at thev higher pressure-forthe time thusdetermined;` Normally the casing of' the relief-valve andf supplemental: reservoir 1:9.-will contain air at atmospheric pressure, beingv in` communication with the brake-cylinder, whichnormally is open. to the-atmospherel whiley the train is running orstandingwith the brakes-released When an emergencyfapplicationv of. thebrakes is made withthe'parts proportioned as:above assumed, the auxiliary. reservoir will'y beplaced by the-triple valve in communicationv with the brake-cylinder andithe pressui'ewill' equalize in the auxiliary reservoir and brake-- cylinder at approximately eighty-five' pounds, which pressure will also be exerted through the'inlet-passage 17T and atV the inside of the partition. 12 in the movable-abutment of' the relief-valve The, liuid'will flow under this.- pressure through. the passage 118, and' thus will gradually raise the pressure in the. diaphragm-chamber of the relief-valve, wherein it willact upon the greater partof the area of thel movable abutment. rlhe pressure outside of the partition-zl e., beyond it relative to the brake-eylinder-will thus increase at a delinite time-rate and with the proportions before assumed will in ten seconds rise to sixty poundsV tothe square. inch, which acting upon the upper surface ot' the movable abutment willovercome-the spring-9, and thus depress the movable abutment and unseat thevalve l5. The unseating-of'the-valve15will' permit the-brake-cyl-inder pressure ot' approximately eighty-tive-.pounds tobe exerted practically instantaneously over the entire area of the` movable abutment, thus strongly overpowering the spring 9 and causing the movable abutmenttoI travelito the full limit of its movement, where it isarrested, as shown in Fig. 2, by Iengagement with the upper. endol thespring-chamber.

Inthe latter part of the travel; ot the movable abutment the valve 13. is arrested, andK its seat moving from it leaves the passage through the movable abutment open, so that airl'lowsrom the brake-cylinder through the movable abutment past the relief-valve 13 and linally through the escape-1 )assages 22 to theatmosphere, this. liow continuing untilthe b ako-cylinder pressure is reducedy to the point counterbalanced' by the spring 9, the pressure of. which will then move back the movable abutmentA and seat the valves 1?) and 15, restoring the parts to the normal'position, (shown in; Fig. 1,) but with the brake-cylinder pressure-lowered to the point determined by the force of the spring 9' of the reliefvalve-71e., with the proportions assumed. to the pressure ot' sixty pounds to: the square inch. So longI as. the pressure exerted in the brake-cylinder doesnot exceed this point, the relief-valve will remain closed andthe brake apparatus will operate the same as if the relief-valere were'not a part ot' the-same.

In making service'applications-of the brakes the-air ispermitted to liow from the auxiliary reservoir into thebrake-cylinder at a relatively slow rate as compared with that at which the airA enters` in4 makingemergency applications, in which the brake-cylinder is charged with maximum pressure as rapidly as possible.

`Ordinarily in making service applications the air is admittedtothe brake-cylinder-in several successive operations, the engineer at rst reducing the'train-pipe pressure so as toadmit a moderate pressure olvl`l air to the brake-cylinder, which is: then retained therein and augmented from time to time by the engineer, who causes the successive additions ol airprcssure to be made according to his judgment, so as to bring the train to a standstill at the-desired point, which maybe done without utilizingy the full pressure attainable in.

the# brake-cylinders and as commonly done requires-thefull pressure, if at all, only shortly before the train is brought to a standstill. In the usual:manipulation of the brakes, therefore, the pressure has time to equalize in the diaphragnrehamber of the relief-valve lorming the` subject of this invention with the brake-cylinder pressure after the lirst partial admission of air to the brake-eylimler and before-the pressure has been augmented therein, and so on alitereach successive increase in ai-rpressure, so that by the time that the brake-cylinder pressure has risen to the maximum desired lor the service applications, assumed in thiscase to be sixty pounds to the square inch, the pressure in the diaphragmchamber will also have risen nearly to sixty pounds tothe square inch, and any further increase in brake-cylinder pressure will therefore almost immediately produce sullieient pressure on the movable abutment to over- .lOO

come the spring 9 and' cause the relief-valve to open so as to relieve the brake-cylinder of such slight excess of pressure over sixty pounds as may have been required to causel the opening of the relief-valve. When, however, a full service application of the brakes is made as promptly as possible by the engineer, the brake-cylinder pressure, although increasing gradually and slowly as compared with the time required' in making an emergency application, may increase at a more rapid rate than the pressure inthe diaphragmchamber increases byadmssion ofair through the by-pass 18. In making the regular full service application,for example, the brakecylinder pressure may rise to sixty pounds in aninterval'oil four or five seconds, while with the proportions assumed it would require more than ten seconds for the pressure in the diaphragm-chamber to rise to sixty pounds, as the airwould be flowing through the by-pass 18 und er less pressure than is the case in an emergency application in which it was assumed -to acquire sixty pounds pressure in the diaphragm-chamber with the air flowing thereto from a brake-cylinder pressure of eighty-five pounds in an interval of ten seconds. Therefore with the construction shown in Fig. l undcr the conditions last assumed the pressure in full Ypressure of equalization had been attained, which under the conditions of service would generally be before thev speed of the train was sufciently reduced to render the additional brake-cylinder pressure objectionable. If, however, it is desired to relieve the brake-cylinder pressure in service applications as soon as it exceeds the assumed normal maximum pressure of sixty pounds, this may be accomplished by constructing the by-pass so that with the gradual increase of brake-cylinder pressure which takes place in a service application the pressure in the diaphragmchamber will rise substantially as rapidly as the brake-cylinder pressure. y

In the construction shown in Fig. 4, for example, an additional orvsupplemental by-pass 18() is provided, said by-pass or passage from the brake-cylinder to the diaphragm-chamber containing a valve 25, normally held unseated by alight spring 26 and having a passage 27 through the portion of said .valve outside of the area that covers the port-opening controlled by it, which passage 27, in connection withv the by-pass 18, affords suiicient capacity vfor thev i'low of air from the brake-cylinder into the diaphragm-chamber to charge the latter approximately as rapidly as the brake-cylinder pressure increases 1n a service application of the brakes, so that the pressure on both sides of the partition remains approximately equal, and the pressure on the movable abutment rises to sixty pounds by the time that the brake-cylinder pressure has risen to sixty pounds or only slightly in excess thereof. Therefore when the brake-cylinder pressure exceeds sixty pounds the movable abutment will be actuated to open the vent-valve, which then operates as an ordinary safety-valve or relief-valve to prevent further rise in brakecylinder pressure. When,however,the brakecylinder pressure is raised promptly, as in making an emergency application of the brakes, the sudden access of pressure on the piston-valve 25 will overcome its spring 26 Vand seat the said valve, thus closing the supplemental by-pass and permitting the air to iow into the diaphragm-chamber only through the main by-pass 18, so that the apparatus then operates'precisely the same as described in connection with the construction shown in The invention is not limited to the specific construction shown, which may be varied widely in details, another modiication being illustrated. in Fig. 5, wherein the pressure-excluding valve 15 is not of annular form, but seats directly over and closes the inlet-passage 17, while the main by-pass 18 is formed' in a passage from the brake-cylinder connection to the diaphragm-chamber of the pressure-excluding valve 15.

pose explained in connection with Fig. L1, they may be made, as shown, 1n a valve working in the by-pass passage and having the main by- .pass formed within the port-covering portion of the valve, so as to remain open when the 4 valve is seated, while the supplementary by- `pass is formed in or near the periphery of the valve or by a loose t of the valve in the cylindrical chamber in which it works. With a relatively slow increase in the brake-cylinder pressure the air will flow both through and around the piston-valve and charge the diaphragm-chamber approximately as rapidly as the brake-'cylinder is charged; but with a sudp den increase of brake-cylinder pressure, such as produced 1n maklng an emergency appllsure which when suicient produces the de- It' both main and supplementary by-passes are required for the pur- IIO sired movement of said movable abutment. The diaphragm proper, 8, of the movable abutment herein shown serves mainly as a tight packing to cause the fluid-pressure to be fully exerted on the movable abutment without leakage past the same. The term diaphragmchamber, used for convenience, should be understood as referring to the fluid-pressure chamber containing the iiuid which acts directly upon the movable abutment of whatever mechanical construction may be adopted, said abutment being the actuator for the valves proper of the apparatuswnamely, the discharge-valve 13 or relief-valve proper and the pressure-excluding valve 15, which when seated excludes direct or unobstruced access of pressure from the part to be relieved of pressure into the diaphragm-chamber of Huidpressure chamber for the fluid that actuates the movable abutment.

The entire apparatus may be properly called a timed relief-valve, as it operates like an ordinary relief-valve or safety-valve, except that under the proper conditions the time of its opening is deferred for a predetermined interval after vthe pressure in the space to be relieved has been in excess of the amount to which it is lowered by the operation of the relief-valve as soon as said time interval has elapsed.

The diaphragm-chamber, together with the supplemental chamber 19, when required in conjunction with the by-pass around the pressure-excluding valve constitutes a measuring chamber or space, as well as the pressurechamber for the actuating Huid, the said parts determining the time rate at which the pressure in said measuring chamber increases when supplied through the by-pass with air rom a given higher pressure, and thereby measuring and determining the time interval required for the pressure to acquire the requisite amount to actuate the movable abutment and valves connected therewith, and the invention is not limited to the specific mechanical construction shown for providing a measuring chamber or reservoir of the requisite capacity. y

rlhe spring 9 is merely a convenient and usual device for opposing a definite determinable force to the fluid-pressure acting upon the movable abutment so as to cause the movable abutment to move in one or the other direction according as the fluid-pressu re exceeds or becomes less than the said predetermined force, and the invention is not limited to this specific device as the means for furnishing the opposing or counterbalancing force.

While the valve 15 has for convenience been called a pressure-excluding valve, as normally when seated or closed it excludes direct access of pressure to the diaphragm-chamber,

rapidly than it is admitted through the timemeasuring by-pass, so as to allord a prompt increase in pressure at thc moment when the relief-valve proper is to be opened, and thus cause the same to open fully and atlord rapid and practically instantaneous reduction ol pressure. The timed reliei` or deferred operation of the relief-valve might be obtained without this operation oi' the pressure-exclmling valve by utilizing only its function when closed as a partition or portion of the structure serving to separate the space to he relieved Jfrom the space containing the measuring and relief-valve actuating fluid, except lor the time-measuring by-pass or restricted communication between these spaces.

A structure in which the pressurc-exchuling valve was omitted ornot utilized as a valve would be within the invention and would operate as a timed relief-valve, but would open less promptly as the pressure in thc measuring-chamber continued to rise above the point at which it was just suiiicient to open thedischarge-valve or relief-valve proper. 1t is,however, ot' important advantage to provide for the promptand full opening of the relief-val ve as soon as the predetermined time interval has elapsed, as by this construction the brakes may remain applied with the full emergencypressure for the desired predetermined interval of time, after which the pressure will he reduced promptly 'to the predetermined amount, which is more effective for bringing the train t0 a standstill from the slower speed to which it has been brought by the action oi' the brakes under the full emergency-prcssure.

The terms upperf lower, and the like have been used for convenience in identifying the parts as shown in the drawings and are not to be understood as indicating any limitation in the matter of the position in which the parts are arranged or used.

I claim- 1. The combination in an automatic {luidpressure brake system of an auxiliary reservoir, a triple valve, and brakc-cylimler, with a timed relief-valve controlling an escape-passage from the brake cylinder and means whereby the said valve is automatically opened after the expiration oi' a predetermined time interval during which thebrake-cylinder pressure has remained greater than the amount to which it is lowered by said relief-valve, substantially as and for the purpose set forth.

2. A timed relief-valve comprising an cscape-passage and discharge-valve controlling the same, combined with a movable abutment controlling the operation oi said dischargevalve, and -a Huid-pressure chamber for the actuating iluid for said movable abutment and means for normally preventing free communication between said pressure-chamber and the space containing the fluid-pressure to he relieved; and means for slowly admitting lluid to said pressure-chamber whereby the req uilOO llO

- site pressure `to'actuate the movable abutment is acquired after the lapse of a determinable interval of time, substantially as described.

3. ,A timed relief-valve comprising a discliarge-valve controlling an escape-passage, combined with a movable abutment controlling the operation of said discliarge-valve, and a fluid-pressure chamber for the actuating fluid for said movable abutment, and a pressure-excluding valve controlled by said movable abutment, which, when closed, prevents free access of pressure to said chamber; and means for slowly admitting fluid to vsaid pressure-chamber, whereby the requisite pressure to cause the movable abutment to open the said pressure-excluding and discharge valves is acquired after the lapse of a determinable interval of time, substantially as described.

4C. The combination with the'brake-cylinder of a fluid-pressure brake system; of a relief-valve comprising a fluid-discharge valve; a movable abutment controlling the operation thereof, and a pressure-chamber for the actuating iiuid for said 4movable abutment, said Huid-pressure chamber being normally in restricted communication with the brakecylinder; whereby fluidunder pressure passes from the brake-cylinder into the fluid-pressure chamber slowly, and a determinable interval ottime is required to produce suiicient pressure in the pressure-chamber-to actuate the movable abutment, substantially as and for the purpose described.

5. rl`he combination of a discharge-valve controlling a passage from a space to be relieved, with a movable abutment controlling the operation of said discharge-valve, and a pressure-chamber for the actuating iiuid for said movable abutment, the said pressurechamber -being normally in restricted communication with the space to be relieved, whereby Huid-pressure may be maintained in the space to be relieved greater than the pressure required to actuate the movable abutment during an interval of time in which the pressure-chamber is being charged from the space to be relieved through the restricted connecting-passage, substantially as described.

6. The combination of'a' discharge-valve controlling a passage from a space to be relieved, with a movable abutment controlling the operation of said discharge-valve, and a pressure-chamber for the actuating fluid for said movable abutment, the' said pressurechamber being normally in restricted communication with the space to be relieved; and a pressure-excluding valve which,when open', establishes free communication between the pressure-chamber and space to be relieved, whereby Huid-pressure may be maintained in the space to be relieved greater than the pressure required to actuate the movable abut.

ment during an interval of time in vwhich the pressure-chamber is being charged from the said time interval the pressure-excluding' valve is opened to admit Huid into the pressure-chamber freely from the space to be relieved, thereby causing the discharge-valve to be opened-to afford prompt relierl of the pressure.

7. The combination of a discharge-valve controlling a passage from a space to be relieved, and a movable abutment controlling the operation of said discharge-valve, and a pressure-chamber for the actuating fluid for said movable abutment, and a pressure-excluding valve also controlled by said movable abutment, which valve, when closed, prevents, and when open establishes, free communication between the pressure-chamber and space to be relieved, and main and supplemental bypasses affording restricted communication between said pressure-cliamber and the space to be relieved; and means for closing said supplemental by-pass when the pressure in the space to be relieved is suddenly increased,

whereby the pressure in the pressure-cliami ber increases in approximate equality with that in the space to be relieved when the pressure rises slowly in the latter, but is maintained substantially lower than the pressure in the space to be relieved for adeterminable interval of'time when said pressure is suddenly increased.

8. The combination of a dischargevalve controlling a passage from a space to be relieved; a movable abutment controlling the operation of said discharge-valve, and a measuring pressure-chamber for the actuating iiuid for said movable abutment, said chamber being normally in communication with the space to be relieved through a small passage, whereby Huid-pressure may be maintained in the space to be relieved greater than the pressure required to actuate the movable abutment during an interval of time dependent upon the capacity of the measuring-chamber and small passage connecting the same with the space to be relieved.

9. The combination of a discharge-valve controlling apassage from a space to be relieved; a movable abutment controlling the operation of said discliarge-valve; a measuring pressure-chamber for the actuating fluid Jfor said movable abutment; a pressure-excluding valve controlled by said movable abutment, which valve, when closed, prevents, and when open establishes, free communication between IOO IIO

the pressure-chamber and space to be rev able abutment, during an interval of time dependent upon the capacity of the said measuring-ehamber and bypass, Substantially as and for the purpose described.

10. The combination of the discharge-valve controlling a passage* from a space to be relieved; amovable abutment controlling the operation of said discharge-valve; a measuring pressure-ehamber for the actuating Huid for Said movable abutment, a pressure-excluding valve controlled by said movable abutment, which valve, When closed, prevents, and when open establishes, free communication between the pressure-chamber and space to be relieved; with main and supplemental b v-passes affording' restricted `communication between the Said measuring presenre-ehamber and the space to be relieved; and means for closing' Said supplemental by-pass when the pressure is suddenly introduced into the space to berelieved.

In testimony whereof I have signed my name to this specification in the presence ol two sul)- seribing witnesses.

JOHN lV. BlMlLlCY.

Titnessesz W. F. NIeoL, JNO. F. MALoNuY. 

